1. Field of the Invention
The present invention relates to reflect type displays and more particularly, to liquid crystal displays which realize to reduce the thickness of the display portion of microcomputers, word processors, televisions, and the like by the provision of a display panel that uses smectic liquid crystal with an added dye, for instance, a ferroelectric liquid crystal (referred to as FLC hereinafter) of the guest-host type, in particular.
2. Description of the Prior Art
Of the solid state display panel, the system which controls each picture element independently is effective for displays with large area. As such a panel there has been known in the past a display in which the multiplexing drive system is applied to a simple matrix structure of the A4 size with 400 elements in the row and 200 elements in the column direction that is formed by the use of a two-frequency liquid crystal, for instance, a twistic nematic liquid crystal (referred to as TN liquid crystal hereinafter). However, to construct a reflection type liquid crystal display by the use such a TN liquid crystal, two-polarizing plates have to be arranged on the outside of a pair of substrates, rotated mutually by 90.degree.. Moreover, a reflecting plate has to be arranged on the outside (namely, on the furthest side with respect to the incident light) of the polarizing plate. Namely, the light path is as follows: The incident light goes through a first polarizing plate, an opposing glass, an opposing transparent conducting film, TN liquid crystals, a transparent conducting film, a glass substrate, a second polarizing plate, and an aluminium reflecting substrate.
Further, light reflected there proceeds backward to the incidence side through the second polarizing plate. However, use of such TN crystals has many drawbacks such as those listed below.
(1) The amount of reflected light is reduced due to the use of two polarizing plates.
(2) There is observed a loss of light due to absorption of light by the glass substrates.
(3) The reflecting plate becomes cloudy due to oxidation of aluminum by the atmosphere, which induces a reduction in the reflectivity.
(4) When active elements are provided on the inside of the substrate, there is generated an absorption loss caused by the organic resin that exists in these surroundings.
The present invention is aimed at solving these problems.